This invention relates to a novel catalyst system useful in the preparation of organic urethanes from an organic nitro compound, carbon monoxide, and an organic compound containing at least one hydroxyl.
Organic urethanes are used extensively as foams, fibers and coatings in a variety of industries.
Organic urethanes have been prepared commercially in the past by reacting an isocyanate with a compound contining a hydroxyl group under elevated temperature conditions. Expense of the isocyanate starting compounds and toxicity problems with the isocyanates are drawbacks to this approach. More recently organic urethanes have been prepared by reacting an organic compound containing at least one hydroxyl group with carbon monoxide and an organic nitro compound. For example, such a process employing a metal carbonyl as the catalyst is disclosed in U.S. Pat. No. 3,338,956. A catalyst useful for the production of urethanes comprising palladium or a palladium compound and a transition metal compound is disclosed in U.S. Pat. No. 4,219,661. In this patent, the use of a tertiary amine as a third component in the catalyst system is also disclosed.